Android6.0之后,權(quán)限分為install時的權(quán)限跟運(yùn)行時權(quán)限逊笆,如果我們的targetSdkVersion>=23难裆,install權(quán)限同runtime權(quán)限是分開的乃戈,app也要針對6.0已經(jīng)做適配症虑,沒什么大問題谍憔,無論運(yùn)行在舊版本還是6.0之后的手機(jī)上都o(jì)k习贫,這也是Google推薦的適配方案苫昌。但是如果targetSdkVersion < 23 ,在6.0之后的手機(jī)上就會遇到一些問題蜡歹,因?yàn)樵谶@種情況下默認(rèn)權(quán)限是全部授予的月而,但是可能會被用戶手動取消父款,而Context的checkSelfPermission權(quán)限檢查接口也會失效憨攒,因?yàn)檫@個API接口6.0之后用的是runtime-permission的模型肝集,而targetSdkVersion < 23 時候杏瞻,app只有intalled的權(quán)限,其granted值一直是true浮创,也可以看做是全部是授權(quán)了的斩披,就算在設(shè)置里面取消授權(quán)也不會影響installed權(quán)限的granted,而Context的checkSelfPermission的接口卻是用granted這個值作為授權(quán)與否的參考仍劈,所以如果用這個接口耳奕,那得到的一定是授權(quán)了屋群,是不準(zhǔn)確的芍躏,如下:targetSdkVersion < 23的時候对竣,package信息中的權(quán)限包含app申請的全部權(quán)限,
<package name="com.snail.labaffinity" codePath="/data/app/com.snail.labaffinity-1" nativeLibraryPath="/data/app/com.snail.labaffinity-1/lib" publicFlags="944291398" privateFlags="0" ft="15f0f58e548" it="15f0f58e548" ut="15f0f58e548" version="1" userId="10084">
<perms>
<item name="android.permission.ACCESS_FINE_LOCATION" granted="true" flags="0" />
<item name="android.permission.INTERNET" granted="true" flags="0" />
<item name="android.permission.READ_EXTERNAL_STORAGE" granted="true" flags="0" />
<item name="android.permission.ACCESS_COARSE_LOCATION" granted="true" flags="0" />
<item name="android.permission.READ_PHONE_STATE" granted="true" flags="0" />
<item name="android.permission.CALL_PHONE" granted="true" flags="0" />
<item name="android.permission.CAMERA" granted="true" flags="0" />
<item name="android.permission.WRITE_EXTERNAL_STORAGE" granted="true" flags="0" />
<item name="android.permission.READ_CONTACTS" granted="true" flags="0" />
</perms>
<proper-signing-keyset identifier="18" />
</package>
這種情況下吕晌,該做法就會引發(fā)問題睛驳,先從源碼看一下為什么targetSdkVersion < 23 Context 的 checkSelfPermission方法失效乏沸,之后再看下在targetSdkVersion < 23 的時候蹬跃,如何判斷6.0的手機(jī)是否被授權(quán)蝶缀。
為什么targetSdkVersion < 23 Context 的 checkSelfPermission失效
跟蹤一下源碼發(fā)現(xiàn)Context 的 checkSelfPermission最終會調(diào)用ContextImp的checkPermission扼劈,最終調(diào)用
@Override
public int checkPermission(String permission, int pid, int uid) {
if (permission == null) {
throw new IllegalArgumentException("permission is null");
}
try {
return ActivityManagerNative.getDefault().checkPermission(
permission, pid, uid);
} catch (RemoteException e) {
return PackageManager.PERMISSION_DENIED;
}
}
最終請求ActivityManagerService的checkPermission,經(jīng)過預(yù)處理跟中轉(zhuǎn)最后會調(diào)用PackageManagerService的checkUidPermission
@Override
public int checkUidPermission(String permName, int uid) {
final int userId = UserHandle.getUserId(uid);
synchronized (mPackages) {
<!--查詢權(quán)限-->
Object obj = mSettings.getUserIdLPr(UserHandle.getAppId(uid));
if (obj != null) {
final SettingBase ps = (SettingBase) obj;
final PermissionsState permissionsState = ps.getPermissionsState();
<!--檢驗(yàn)授權(quán)-->
if (permissionsState.hasPermission(permName, userId)) {
return PackageManager.PERMISSION_GRANTED;
}
if (Manifest.permission.ACCESS_COARSE_LOCATION.equals(permName) && permissionsState
.hasPermission(Manifest.permission.ACCESS_FINE_LOCATION, userId)) {
return PackageManager.PERMISSION_GRANTED;
}
} ... }
return PackageManager.PERMISSION_DENIED;
}
PackageManagerService會從mSettings全局變量中獲取權(quán)限先煎,然后進(jìn)一步驗(yàn)證權(quán)限是否被授予
public boolean hasPermission(String name, int userId) {
enforceValidUserId(userId);
if (mPermissions == null) {
return false;
}
PermissionData permissionData = mPermissions.get(name);
return permissionData != null && permissionData.isGranted(userId);
}
這里的檢查點(diǎn)只有兩點(diǎn)薯蝎,第一個是是否有這個權(quán)限,第二是是否是Granted缩筛,對于targetSdkVersion<23的所有的權(quán)限都在packages.xml中瞎抛,grante一直是true桐臊,無法被跟新断凶,為什么無法被更新呢飘弧?看一下6.0之后的授權(quán)與取消授權(quán)的函數(shù),首先看一個變量mAppSupportsRuntimePermissions
mAppSupportsRuntimePermissions = packageInfo.applicationInfo
.targetSdkVersion > Build.VERSION_CODES.LOLLIPOP_MR1;
mAppOps = context.getSystemService(AppOpsManager.class);
mAppSupportsRuntimePermissions定義在AppPermissionGroup中,6.0之后權(quán)限都是分組的赶撰,對于targetSdkVersion<23的APP來說豪娜,很明顯是不支持動態(tài)權(quán)限管理的瘤载,那么授權(quán)跟取消授權(quán)函數(shù)就很不一樣如下: 授權(quán)函數(shù)
public boolean grantRuntimePermissions(boolean fixedByTheUser, String[] filterPermissions) {
final int uid = mPackageInfo.applicationInfo.uid;
for (Permission permission : mPermissions.values()) {
if (filterPermissions != null
&& !ArrayUtils.contains(filterPermissions, permission.getName())) {
continue;
}
<!--關(guān)鍵點(diǎn)1 如果支持鸣奔,也即是targetSdkVersion>23那走6.0動態(tài)權(quán)限管理那一套-->
if (mAppSupportsRuntimePermissions) {
// Do not touch permissions fixed by the system.
if (permission.isSystemFixed()) {
return false;
}
// Ensure the permission app op enabled before the permission grant.
if (permission.hasAppOp() && !permission.isAppOpAllowed()) {
permission.setAppOpAllowed(true);
mAppOps.setUidMode(permission.getAppOp(), uid, AppOpsManager.MODE_ALLOWED);
}
// Grant the permission if needed.
if (!permission.isGranted()) {
permission.setGranted(true);
<!--關(guān)鍵點(diǎn)2更新其runtime-permission.xml 中g(shù)ranted值-->
mPackageManager.grantRuntimePermission(mPackageInfo.packageName,
permission.getName(), mUserHandle);
}
...
} else {
if (!permission.isGranted()) {
continue;
}
int killUid = -1;
int mask = 0;
if (permission.hasAppOp()) {
if (!permission.isAppOpAllowed()) {
permission.setAppOpAllowed(true);
<!--關(guān)鍵點(diǎn)3 設(shè)置為AppOpsManager.MODE_ALLOWED-->
mAppOps.setUidMode(permission.getAppOp(), uid, AppOpsManager.MODE_ALLOWED);
killUid = uid;
}
}
<!--關(guān)鍵點(diǎn)4 更新其PermissionFlags-->
if (mask != 0) {
mPackageManager.updatePermissionFlags(permission.getName(),
mPackageInfo.packageName, mask, 0, mUserHandle);
}
}
}
return true;
}
可以看出6.0之后的手機(jī)断楷,針對targetSdkVersion是否高于23做了不同處理冬筒,如果targetSdkVersion>=23支持動態(tài)權(quán)限管理舞痰,那就更新動態(tài)權(quán)限匀奏,并將其持久化到runtime-permission.xml中娃善,并更新其granted值聚磺,如果targetSdkVersion<23 ,也即是不知道6.0的動態(tài)管理瘫寝,那就只更新AppOps,這是4.3引入的老的動態(tài)權(quán)限管理模型首启,不過這里主要是將權(quán)限持久化到appops.xml中毅桃,不過對于其granted的值是沒有做任何更新的钥飞,僅僅是更新了packages.xml中的flag读宙,這個flag可以配合appops.xml標(biāo)識是否被授權(quán)(對于targetSdkVersion<23的適用),以上就是為什么context checkSelfPermission會失效的原因膀估,涉及代碼很多耻讽,不一一列舉针肥,對于取消授權(quán)revokeRuntimePermissions函數(shù),模型一樣具帮,不在贅述蜂厅,那下面看第二個問題掘猿,如何檢查targetSdkVersion<23 app 在6.0以上手機(jī)的權(quán)限呢? Google給了一個兼容類PermissionChecker唇跨,這個類可以間接使用AppOpsService那一套邏輯稠通,獲取到權(quán)限是否被授予衬衬。
targetSdkVersion < 23 的時候,如何判斷6.0的手機(jī)是否被授權(quán)
targetSdkVersion < 23的時候改橘,6.0權(quán)限檢查API失效了滋尉,不過通過上面的分析指導(dǎo),在設(shè)置中權(quán)限的操作仍然會被存儲內(nèi)存及持久化到appops.xml文件中兼砖,這里就是走的AppOpsService那一套,AppOpsService可以看做6.0為了兼容老APP而保留的一個附加的權(quán)限管理模型既棺,在6.0之后的系統(tǒng)中讽挟,可以看做runtime權(quán)限管理的補(bǔ)充,其實(shí)AppOpsService這套在4.3就推出了丸冕,不過不太靈活耽梅,基本沒啥作用,之前只用到了通知管理胖烛⊙劢悖看一下Google提供的一個兼容類PermissionChecker如何做的:
public static int checkPermission(@NonNull Context context, @NonNull String permission,
int pid, int uid, String packageName) {
<!--對于targetSdkVersion < 23 一定是true-->
if (context.checkPermission(permission, pid, uid) == PackageManager.PERMISSION_DENIED) {
return PERMISSION_DENIED;
}
String op = AppOpsManagerCompat.permissionToOp(permission);
<!--看看這個權(quán)限是不是能夠操作,動態(tài)授權(quán)與取消授權(quán) 如果不能佩番,說明權(quán)限一直有-->
if (op == null) {
return PERMISSION_GRANTED;
}
<!--如果能夠取消授權(quán)众旗,就看現(xiàn)在是不是處于權(quán)限被允許的狀態(tài),如果不是趟畏,那就是用戶主動關(guān)閉了權(quán)限-->
if (AppOpsManagerCompat.noteProxyOp(context, op, packageName)
!= AppOpsManagerCompat.MODE_ALLOWED) {
return PERMISSION_DENIED_APP_OP;
}
return PERMISSION_GRANTED;
}
對于6.0之后的手機(jī)AppOpsManagerCompat.noteProxyOp會調(diào)用AppOpsManager23的noteProxyOp贡歧,
private static class AppOpsManagerImpl {
public String permissionToOp(String permission) {
return null;
}
public int noteOp(Context context, String op, int uid, String packageName) {
return MODE_IGNORED;
}
public int noteProxyOp(Context context, String op, String proxiedPackageName) {
return MODE_IGNORED;
}
}
private static class AppOpsManager23 extends AppOpsManagerImpl {
@Override
public String permissionToOp(String permission) {
return AppOpsManagerCompat23.permissionToOp(permission);
}
@Override
public int noteOp(Context context, String op, int uid, String packageName) {
return AppOpsManagerCompat23.noteOp(context, op, uid, packageName);
}
@Override
public int noteProxyOp(Context context, String op, String proxiedPackageName) {
return AppOpsManagerCompat23.noteProxyOp(context, op, proxiedPackageName);
}
}
上面的是6.0之前對應(yīng)的API,下面的是6.0及其之后對應(yīng)的接口赋秀,AppOpsManagerCompat23.noteProxyOp會進(jìn)一步調(diào)用AppOpsManager的noteProxyOp向AppOpsService發(fā)送請求
public static int noteProxyOp(Context context, String op, String proxiedPackageName) {
AppOpsManager appOpsManager = context.getSystemService(AppOpsManager.class);
return appOpsManager.noteProxyOp(op, proxiedPackageName);
}
最后看一下AppOpsService如何檢查權(quán)限
private int noteOperationUnchecked(int code, int uid, String packageName,
int proxyUid, String proxyPackageName) {
synchronized (this) {
Ops ops = getOpsLocked(uid, packageName, true);
Op op = getOpLocked(ops, code, true);
if (isOpRestricted(uid, code, packageName)) {
return AppOpsManager.MODE_IGNORED;
}
op.duration = 0;
final int switchCode = AppOpsManager.opToSwitch(code);
UidState uidState = ops.uidState;
if (uidState.opModes != null) {
final int uidMode = uidState.opModes.get(switchCode);
op.rejectTime = System.currentTimeMillis();
return uidMode;
}
}
final Op switchOp = switchCode != code ? getOpLocked(ops, switchCode, true) : op;
if (switchOp.mode != AppOpsManager.MODE_ALLOWED) {
op.rejectTime = System.currentTimeMillis();
return switchOp.mode;
}
op.time = System.currentTimeMillis();
op.rejectTime = 0;
op.proxyUid = proxyUid;
op.proxyPackageName = proxyPackageName;
return AppOpsManager.MODE_ALLOWED;
}
}
UidState可以看做每個應(yīng)用對應(yīng)的權(quán)限模型利朵,這里的數(shù)據(jù)是有一部分是從appops.xml恢復(fù)回來,也有部分是在更新權(quán)限時候加進(jìn)去的猎莲,這部分變化最終都要持久化到appops.xml中去绍弟,不過持久化比較滯后,一般要等到手機(jī)更新權(quán)限后30分鐘才會持久化到appops.xml中著洼,這里的數(shù)據(jù)一般是在啟動的時候被恢復(fù)重建樟遣,在啟動ActivityManagerService服務(wù)的時候,會在其構(gòu)造函數(shù)總啟動AppOpsService服務(wù):
public ActivityManagerService(Context systemContext) {
...
mAppOpsService = new AppOpsService(new File(systemDir, "appops.xml"), mHandler);
...}
在AppOpsService的構(gòu)造函數(shù)中會將持久化到appops.xml中的權(quán)限信息恢復(fù)出來身笤,并存到內(nèi)存中去豹悬,
public AppOpsService(File storagePath, Handler handler) {
mFile = new AtomicFile(storagePath);
mHandler = handler;
// 新建的時候就會讀取
readState();
}
readState就是將持久化的UidState數(shù)據(jù)給重新讀取出來,如下mFile其實(shí)就是appops.xml的文件對象
void readState() {
synchronized (mFile) {
synchronized (this) {
FileInputStream stream;
try {
stream = mFile.openRead();
} catch (FileNotFoundException e) {
}
boolean success = false;
mUidStates.clear();
try {
XmlPullParser parser = Xml.newPullParser();
parser.setInput(stream, StandardCharsets.UTF_8.name());
int type;
int outerDepth = parser.getDepth();
while ((type = parser.next()) != XmlPullParser.END_DOCUMENT
&& (type != XmlPullParser.END_TAG || parser.getDepth() > outerDepth)) {
if (type == XmlPullParser.END_TAG || type == XmlPullParser.TEXT) {
continue;
}
String tagName = parser.getName();
if (tagName.equals("pkg")) {
readPackage(parser);
} else if (tagName.equals("uid")) {
readUidOps(parser);
} else {
XmlUtils.skipCurrentTag(parser);
}
}
success = true;
...}
讀取之后展鸡,當(dāng)用戶操作權(quán)限的時候屿衅,也會隨機(jī)的更新這里的標(biāo)記,只看下targetSdkVersion<23的莹弊,
public boolean grantRuntimePermissions(boolean fixedByTheUser, String[] filterPermissions) {
final int uid = mPackageInfo.applicationInfo.uid;
for (Permission permission : mPermissions.values()) {
if (filterPermissions != null
&& !ArrayUtils.contains(filterPermissions, permission.getName())) {
continue;
}
<!--關(guān)鍵點(diǎn)1 如果支持涤久,也即是targetSdkVersion>23那走6.0動態(tài)權(quán)限管理那一套-->
if (mAppSupportsRuntimePermissions) {
...
} else {
if (!permission.isGranted()) {
continue;
}
int killUid = -1;
int mask = 0;
if (permission.hasAppOp()) {
if (!permission.isAppOpAllowed()) {
permission.setAppOpAllowed(true);
<!--關(guān)鍵點(diǎn)3 設(shè)置為AppOpsManager.MODE_ALLOWED-->
mAppOps.setUidMode(permission.getAppOp(), uid, AppOpsManager.MODE_ALLOWED);
killUid = uid;
}
}
if (mask != 0) {
mPackageManager.updatePermissionFlags(permission.getName(),
mPackageInfo.packageName, mask, 0, mUserHandle);
}
}
}
return true;
}
拿授權(quán)的場景來說涡尘,其實(shí)關(guān)鍵就是 mAppOps.setUidMode(permission.getAppOp(), uid, AppOpsManager.MODE_ALLOWED)函數(shù),這個函數(shù)會更新AppOpsService中對于權(quán)限的標(biāo)記响迂,并將權(quán)限是否授予的信息持久化到appops.xml及packages.xml考抄,不同版本可能有差別,有可能需要appops.xml跟packages.xml配合才能確定是否授予權(quán)限蔗彤,具體沒深究川梅,有興趣可以自行分析。
@Override
public void setUidMode(int code, int uid, int mode) {
if (Binder.getCallingPid() != Process.myPid()) {
mContext.enforcePermission(android.Manifest.permission.UPDATE_APP_OPS_STATS,
Binder.getCallingPid(), Binder.getCallingUid(), null);
}
verifyIncomingOp(code);
code = AppOpsManager.opToSwitch(code);
synchronized (this) {
final int defaultMode = AppOpsManager.opToDefaultMode(code);
<!--更新操作權(quán)限-->
UidState uidState = getUidStateLocked(uid, false);
if (uidState == null) {
if (mode == defaultMode) {
return;
}
uidState = new UidState(uid);
uidState.opModes = new SparseIntArray();
uidState.opModes.put(code, mode);
mUidStates.put(uid, uidState);
scheduleWriteLocked();
} else if (uidState.opModes == null) {
if (mode != defaultMode) {
uidState.opModes = new SparseIntArray();
uidState.opModes.put(code, mode);
scheduleWriteLocked();
}
} else {
if (uidState.opModes.get(code) == mode) {
return;
}
if (mode == defaultMode) {
uidState.opModes.delete(code);
if (uidState.opModes.size() <= 0) {
uidState.opModes = null;
}
} else {
uidState.opModes.put(code, mode);
}
<!--持久化到appops.xml-->
scheduleWriteLocked();
}
}
...
}
這里有一點(diǎn)注意:scheduleWriteLocked并不是立即執(zhí)行寫操作然遏,而是比更新內(nèi)存滯后贫途,一般滯后30分鐘
static final long WRITE_DELAY = DEBUG ? 1000 : 30*60*1000;
30分鐘才會去更新 ,不過內(nèi)存中都是最新的 待侵,如果直接刪除appops.xml丢早,然后意外重啟,比如adb reboot bootloader秧倾,那么你的所有AppOpsService權(quán)限標(biāo)記將會被清空怨酝,經(jīng)過驗(yàn)證,是符合預(yù)期的那先,也就說农猬,targetSdkVersion<23的情況下,Android6.0以上的手機(jī)售淡,它的權(quán)限操作是持久化在appops.xml中的斤葱,一般關(guān)機(jī)的時候,會持久化一次勋又,如果還沒來得及持久化苦掘,異常關(guān)機(jī)换帜,就會丟失楔壤,這點(diǎn)同runtime-permission類似,異常關(guān)機(jī)也會丟失惯驼,不信可以試驗(yàn)一下 蹲嚣。
在targetSdkVersion>=23的時候,對于 SDK>=23的機(jī)器如何檢測權(quán)限
targetSdkVersion>=23系統(tǒng)已經(jīng)提供了比較合理的檢測手段祟牲,PermisionChecker的checkPermission就可以隙畜,不過,這里需要注意的是说贝,AppOpsService對于targetSdkVersion>=23的時候就不能用了议惰,這里可能是Android的一個bug,當(dāng)targetSdkVersion>=23而SDK_Version>=23的乡恕,對于AppOpsService言询,權(quán)限的授予跟撤銷不是配對的俯萎,如下,先簡單看下授權(quán):
public boolean grantRuntimePermissions(boolean fixedByTheUser, String[] filterPermissions) {
final int uid = mPackageInfo.applicationInfo.uid;
for (Permission permission : mPermissions.values()) {
if (mAppSupportsRuntimePermissions) {
<!--關(guān)鍵點(diǎn)1 同時更新runtim-permission及Appops-->
if (permission.hasAppOp() && !permission.isAppOpAllowed()) {
permission.setAppOpAllowed(true);
mAppOps.setUidMode(permission.getAppOp(), uid, AppOpsManager.MODE_ALLOWED);
}
if (!permission.isGranted()) {
permission.setGranted(true);
mPackageManager.grantRuntimePermission(mPackageInfo.packageName,
permission.getName(), mUserHandle);
}
} else {
if (!permission.isGranted()) {
continue;
}
int killUid = -1;
int mask = 0;
<!--關(guān)鍵點(diǎn)2 更新Appops-->
if (permission.hasAppOp()) {
if (!permission.isAppOpAllowed()) {
permission.setAppOpAllowed(true);
// Enable the app op.
mAppOps.setUidMode(permission.getAppOp(), uid, AppOpsManager.MODE_ALLOWED);
killUid = uid;
}
...
}
}
return true;
}
可見运杭,對于6.0的系統(tǒng)夫啊,無論targetSdkVersion是否>=23,在授權(quán)的時候辆憔,都會更新appops.xml撇眯,那取消授權(quán)呢?
public boolean revokeRuntimePermissions(boolean fixedByTheUser, String[] filterPermissions) {
final int uid = mPackageInfo.applicationInfo.uid;
for (Permission permission : mPermissions.values()) {
...
if (mAppSupportsRuntimePermissions) {
if (permission.isSystemFixed()) {
return false;
}
// Revoke the permission if needed.
if (permission.isGranted()) {
permission.setGranted(false);
mPackageManager.revokeRuntimePermission(mPackageInfo.packageName,
permission.getName(), mUserHandle);
}
<!--關(guān)鍵點(diǎn)1 這里沒有使用mAppOps.setUidMode更新appops.xml文件->
} else {
// Legacy apps cannot have a non-granted permission but just in case.
if (!permission.isGranted()) {
continue;
}
int mask = 0;
int flags = 0;
int killUid = -1;
if (permission.hasAppOp()) {
if (permission.isAppOpAllowed()) {
<!--關(guān)鍵點(diǎn)2 這里使用mAppOps.setUidMode更新appops.xml文件->
mAppOps.setUidMode(permission.getAppOp(), uid, AppOpsManager.MODE_IGNORED);
killUid = uid;
}
...
}
}
return true;
}
看關(guān)鍵點(diǎn)1 虱咧,如果targetSdkVersion>=23在取消授權(quán)的時候熊榛,是不會更新appops.xml的,只有在targetSdkVersion<23的時候腕巡,才會向關(guān)鍵點(diǎn)2来候,撤銷授權(quán)。也就是說對于targetSdkVersion>=23的時候逸雹,不要用AppOpsManager了营搅。
對于6.0以下的手機(jī)權(quán)限如何檢測
對于Android6.0以下的手機(jī),不需要關(guān)心targetVersion梆砸。先說個自己驗(yàn)證的結(jié)果:基本沒法檢測转质,同時也不需要檢測,就算檢測出來也沒有多大意義帖世,因?yàn)樾菪罚|發(fā)時機(jī)是在真正的調(diào)用服務(wù)時候。對于4.3到6.0之前的國產(chǎn)ROM日矫,雖然采用AppopsManagerService赂弓,但是并未按照Google的模型對所有權(quán)限進(jìn)行適配,在這個模型下哪轿,也就適配了兩個權(quán)限盈魁,
- 通知權(quán)限 public static final int OP_POST_NOTIFICATION = 11;
- 懸浮窗權(quán)限 public static final int OP_SYSTEM_ALERT_WINDOW = 24;
Google發(fā)行版的APPOpsService,基本是把整個鑒權(quán)邏輯給屏蔽了窃诉,通過CM的源碼杨耙,課對這部分代碼窺探一斑,如果整個權(quán)限都采用4.3權(quán)限管理模型飘痛,在拒絕一項(xiàng)權(quán)限的時候珊膜,這個操作會被持久化到appops.xml中去,但是具體看下去宣脉,其實(shí)并不是如此车柠,這種機(jī)制只對以上兩個權(quán)限生效:
<pkg n="com.xxx">
<uid n="10988">
<!--關(guān)鍵點(diǎn)1-->
<op n="11" m="1" t="1513145979969" r="1521550658067" />
<op n="12" t="1521550651593" />
<op n="29" t="1521550682769" />
<pkg n="com.wandoujia.phoenix2.usbproxy">
<uid n="10969">
<op n="4" t="1517279031173" />
<!--關(guān)鍵點(diǎn)2-->
<op n="11" m="1" t="1510889291834" r="1517279030708" />
<op n="14" t="1517293452801" />
<!--關(guān)鍵點(diǎn)3-->
<op n="24" m="1" />
<op n="40" t="1513599239364" d="600011" />
國產(chǎn)rom中,假如你拒絕授權(quán)位置權(quán)限,按照AppOpsService模型竹祷,該操作應(yīng)該被持久化到appops.xml中去介蛉,但是,結(jié)果并非如此溶褪,也就是說币旧,對于其他權(quán)限,國產(chǎn)ROM應(yīng)該是自己糊弄了一套持久管理猿妈,持久化Android系統(tǒng)API無法訪問的地方吹菱,僅僅為自身ROM可見。appops.xml真正被系統(tǒng)使用時從Android6.0開始彭则,其實(shí)Android6.0是有兩套權(quán)限管理的鳍刷,這其實(shí)很混亂,不知道Google怎么想的俯抖,不過6.0似乎也有漏洞:權(quán)限的授予跟回收權(quán)限好像并不配對输瓜。
那么這就帶來了一個問題,在Android4.3到Android6.0之間的版本芬萍,并沒有同一個API來檢測是否獲取了某種權(quán)限庇茫,因?yàn)槟銊討B(tài)更新的權(quán)限并未持久化到appops.xml中去馋袜。對于Android6.0之前的ROM匆赃,雖然不能檢測师郑,但完全可以直接用服務(wù),不會崩潰漫蛔,因?yàn)槿绻嫘枰b權(quán)嗜愈,它的鑒權(quán)時機(jī)其實(shí)是在服務(wù)使用的時候。AppopsManager在6.0之前莽龟,只能用來檢測通知蠕嫁,可能還有懸浮窗。
檢查權(quán)限的解決方案(除去通知權(quán)限)
全部采用PermissionChecker的checkSelfPermission:(不要提高compileSdkVersion)
public boolean selfPermissionGranted(Context context, String permission) {
return PermissionChecker.checkSelfPermission(context, permission) == PermissionChecker.PERMISSION_GRANTED;
}
總結(jié)
Android6.0系統(tǒng)其實(shí)支持兩種動態(tài)管理毯盈,runtime-permission及被閹割的AppOpsService剃毒,當(dāng)targetSdkVersion>23的時候,采用rumtime-permission奶镶,當(dāng) targetSdkVersion<23的時候迟赃,兩者兼有,其實(shí)targetSdkVersion<23的時候厂镇,仍然可以動態(tài)申請6.0的權(quán)限,前提是你要采用23之后的compileSdkVersion左刽,只有這樣才能用相應(yīng)的API捺信,不過還是推薦升級targetSdkVersion,這才是正道。對于Android6.0以下的手機(jī)迄靠,除了通知(可能還有懸浮窗)秒咨,其他權(quán)限基本都沒有系統(tǒng)的檢測手段,無論Context的checkPermission還是AppopsManager的checkOp掌挚,基本都是對Android6.0之后才有效雨席。
作者:看書的小蝸牛
原文鏈接:Android權(quán)限檢查API checkSelfPermission問題
僅供參考,歡迎指正